Re: [DNSOP] SVCB without A/AAAA records at the service name

Martin Thomson <mt@lowentropy.net> Sun, 17 January 2021 22:57 UTC

Return-Path: <mt@lowentropy.net>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E07DF3A02BC for <dnsop@ietfa.amsl.com>; Sun, 17 Jan 2021 14:57:03 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.119
X-Spam-Level:
X-Spam-Status: No, score=-2.119 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_BLOCKED=0.001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=lowentropy.net header.b=Jx6tmPji; dkim=pass (2048-bit key) header.d=messagingengine.com header.b=MnY93teT
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id h49ISpvYxSY3 for <dnsop@ietfa.amsl.com>; Sun, 17 Jan 2021 14:57:02 -0800 (PST)
Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 71D103A02BB for <dnsop@ietf.org>; Sun, 17 Jan 2021 14:57:02 -0800 (PST)
Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 055AD5C00A5 for <dnsop@ietf.org>; Sun, 17 Jan 2021 17:57:01 -0500 (EST)
Received: from imap10 ([10.202.2.60]) by compute1.internal (MEProxy); Sun, 17 Jan 2021 17:57:01 -0500
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lowentropy.net; h=mime-version:message-id:in-reply-to:references:date:from:to :subject:content-type; s=fm1; bh=rr/PNzC51Th5SQuSRkolfhzJ0zwUPrl pcTHYv1piw8I=; b=Jx6tmPjihNxW/Q1nyFe5qDAY6cUmSscX4fNE5kfDnz5y+40 snC/N0C3tMKTiWhhhg/Ta8mTLXe26Z0Esszk1l6wiIPVeJq4fO9VXgd3RukpR4tO ua0IjxM+sLyXFBfHJhzJ+L6jxSjbYXgzvyvXfd7zflzpmmuRAjCfwj7OtGxVGT9o wRgH89KH7il6xeSsaGWTgIvnmKrTgcUsTl1M9LR8hgDguyNsE3l2/38B+sSOhVl1 zGmDc1IHR8HbBJBHaI6HxZxM+HnJkYHfYD15Lj9FEBwT53Nf3HZ2EP2FFq+n22LX /P4J+5U8AuJz3SwHY6+dO6xVkTr+g2VimBAtOsw==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=rr/PNz C51Th5SQuSRkolfhzJ0zwUPrlpcTHYv1piw8I=; b=MnY93teTRdAnu8Sm1MIOI8 QsuwYyTD/5F8JqrKD+GbIZ67NlxsnSJlJifFdrjMXyp4J7vk2Jslme+qRTq+PlMa CwXTq25K9DhHF9mbpVY30sedLCWJXxsiRdhvUJwgKYxK6ODwh8a4z1f+aaPlVqNx /TmHrhzcEGH/AFs3D7dyjXq/6RyBbyPNNTfZHdU3G5ggC8hw8GUzn8IOwYQ8WwMa POd4gJOIE1qYX1tvRdGGioUE8G43CmhY6ZBT7muVhorvrdjUm5FKJgWJhRGU9tjA FSbhAHw6GbfSaQhjWbXUUi8dtiSEE6rBC5CrRNlTrvBKnPH5PJ8VU7T1dMU+wdfg ==
X-ME-Sender: <xms:vMAEYF8OMIEEduz8YfBEGTKoBbMzbc7EaVC8K-xsg0Iv7X6dKebpwA> <xme:vMAEYJuU6Rcm8UcJL15GhhaBYDZnoo2v-mHyureEGHPWNHXVQHmjSC-aJHKAI_R4Z YOBLSZQ3OVQj8WyTd0>
X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrtdejgddtfecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepofgfggfkjghffffhvffutgesthdtre dtreertdenucfhrhhomhepfdforghrthhinhcuvfhhohhmshhonhdfuceomhhtsehlohif vghnthhrohhphidrnhgvtheqnecuggftrfgrthhtvghrnheptdeghfekgeffhfetfeejke evfeetheehleegheehveelfeetfeeikeefgfejvdegnecuffhomhgrihhnpehgihhthhhu sgdrtghomhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhroh hmpehmtheslhhofigvnhhtrhhophihrdhnvght
X-ME-Proxy: <xmx:vMAEYDDgO2ooO4siK49fP14TikbtSxyB2Mjx0foMrGaP3o3uOS3WxA> <xmx:vMAEYJcADZijXGx50zMTBRXJaNWtziUf_-F_Ai242dZAa-enscVB5Q> <xmx:vMAEYKOuiCWIz8y7_Nz1TShOWbEGt8NoH1A2m0Ut8OZhY0jVKqgKlg> <xmx:vcAEYAZGKiGG_9e85SYmhhXf7ZkdkzuEEZJv25qoFYFq0IWpsOCmzA>
Received: by mailuser.nyi.internal (Postfix, from userid 501) id AE07D20066; Sun, 17 Jan 2021 17:57:00 -0500 (EST)
X-Mailer: MessagingEngine.com Webmail Interface
User-Agent: Cyrus-JMAP/3.5.0-alpha0-45-g4839256-fm-20210104.001-g48392560
Mime-Version: 1.0
Message-Id: <87098be5-765c-4481-b990-bdb2c936173d@www.fastmail.com>
In-Reply-To: <CAHbrMsCaVER+xDjznjRK4cSjqc+g855GNV2QCfewvCqh=E1FMw@mail.gmail.com>
References: <2e1054a0-5a7a-4d62-92a1-095217af82bb@www.fastmail.com> <CAHbrMsCaVER+xDjznjRK4cSjqc+g855GNV2QCfewvCqh=E1FMw@mail.gmail.com>
Date: Mon, 18 Jan 2021 09:56:42 +1100
From: Martin Thomson <mt@lowentropy.net>
To: dnsop@ietf.org
Content-Type: text/plain
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/nJAy7-oTbhoGmRKdn4C9p5EQMwo>
Subject: Re: [DNSOP] SVCB without A/AAAA records at the service name
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: IETF DNSOP WG mailing list <dnsop.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dnsop>, <mailto:dnsop-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dnsop/>
List-Post: <mailto:dnsop@ietf.org>
List-Help: <mailto:dnsop-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dnsop>, <mailto:dnsop-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 17 Jan 2021 22:57:04 -0000

On Sat, Jan 16, 2021, at 06:01, Ben Schwartz wrote:
> FWIW, I think this is really an editorial question.  
...
> https://github.com/MikeBishop/dns-alt-svc/pull/288
... 
> https://github.com/MikeBishop/dns-alt-svc/pull/289

Neither of these work for me.  Both do the same thing in different ways.  Both are unspecific about what changes might be made to the algorithm.  That leads to far less certainty about how the information is consumed than I think is sensible.

What I'm looking for here is for the specification to describe what happens when the protocol needs to fall back to A/AAAA and what happens when it does not.  The first is important, because that is what HTTP will need.  The second because I think that is a better approach for any new protocol (I had hoped that webtransport would be able to take advantage of this, but they made a different choice for reasons I'm yet to understand).